We seek financial support for participation at the University of Vermont in the Primary Breast Cancer Therapy protocols of the National Surgical Adjuvant Project for Breast and Bowel Cancers (NSABP). Since 1972 we have placed 167 patients on NSABP protocols and 137 patients are currently alive and under follow-up. We anticipate continued patient entry of approximately 45 patients per year. The NSABP project headquarters proposal should be sought for details of protocol rationale and overall scientific achievements of the NSABP. The availability of this patient population at our Clinical Research Center will make possible the studies on the effect of adjuvant chemotherapy on erythroid and myeloid bone marrow progenitor cell numbers and proliferative rates although funds for the latter studies are not sought in this application.